BROOK LIFE. I51 



structure. Note especially the following : The great 

 length of the legs, which enables the larva to pull 

 itself along without exposing much of its body ; the 

 firmer covering of the fore part of the body which 

 is exposed while the insect is walking ; the softer 

 texture and paler color of the protected parts of the 

 body ; the number, form, and position of the tracheal 

 gills ; and the hooks at the hind end of the body by 

 which the larva holds itself within its case. 



Preserve larvse with their cases in alcohol, and 

 mount empty cases on cards. Try to rear pupae and 

 adults from larvag kept in aquaria. 



Place specimens of larvae, cases, pupae, and adults 

 in your collection under a copy of the following 

 label :— 



Order Trichoptera (Tri-chop'te-ra). 



The Caddice-flies or Caddice-worms. 



Write an account of your observations on these 

 insects, and illustrate it with sketches of their cases. 



The Net-building Caddice-worms {Field and 

 School Work). — In lifting stones from a stream where 

 the current flows swiftly, the collector often finds 

 attached to the lower side of the stones little masses 

 of pebbles which are fastened to each other and to 

 the larger stone by threads of silk. These are the 

 homes of the net-building caddice-worms. 



Pull these rude habitations apart and the owners 

 will be found in more or less perfect tubes of silk. 

 Very little respect for the architectural skill of these 

 builders is commanded by their dwellings. But if 

 one looks a little farther something will be found 

 that is sure to excite admiration. The dweller with^ 



